In addition to the typical stressors experienced by children entering middle school, children in foster care face additional challenges resulting from their maltreatment histories, from unpredictable changes in their living situations, and from losses/gains of parent figures. This vulnerability may be especially pronounced for girls in foster care, who (in addition to being at risk for developing conduct and substance use problems) are at risk for early pregnancy. Social failures in middle school can initiate a set of processes with cascading negative effects that encompass behavioral, social, school, and emotional domains. Despite such risks, girls are less likely to receive specialty mental health or school-based services than their male counterparts. The proposed work extends our prior research to test the efficacy of a preventative intervention for preadolescent girls living in foster/kinship care (N = 90). The intervention is aimed at preventing girls' delinquency, association with deviant peers, initiation of substance use, risky sexual behavior (including the contraction of STDs), school truancy/failure, and mental health problems. The experimental group will be randomly assigned to receive a tri-modal intervention: parent management training for the foster/kin parents prior to the girls' entry into the sixth grade; skill-building sessions for the girls prior to their entry into the sixth grade; and ongoing support and training for foster/kinship parents and girls throughout the sixth grade year. A multimethod, multiagent data collection approach will be used, with assessment occurring at baseline, 6-, 12-, and 18-months. Analyses will examine group differences in proximal and longer-term outcomes based on group assignment (intervention or control); the mediational effects of effective parenting and the girl's social competence on the relationship between group assignment and proximal outcomes; and general developmental modeling and theory-building questions specific to girls.